Engineering the Solid Electrolyte Interphase for Enhancing High-Rate Cycling and Temperature Adaptability of Lithium-Ion Batteries

In overcoming the barrier of rapid Li+ transfer in lithium-ion batteries under extreme temperatures, the desolvation process and interfacial charge transport play critical roles. However, tunning the solvation structure and designing kinetically-stable electrode-electrolyte interface to achieve high-rate charging and discharging remains challenges. Here, a lithium nonafluoro-1-butanesulfonate (NFSALi) additive is introduced to optimize a stability and robust solid electrolyte interface film (SEI), realizing the rapid Li+ transfer process and the structural integrity of electrode materials. The NFSALi-derived thinner, fluorine-rich, and sulfur-containing SEI in nitrile-assistant carbonate electrolytes effectively suppresses decomposition of valeronitrile solvent during high-rate cycling and wide-temperature operation (−40~55 ℃). More importantly, the graphiteǁLiNi0.5Co0.2Mn0.3O2 pouch cell demonstrates a capacity retention of 66.88% after 200 high-rate cycles with 3 C charging and 5 C discharging at a high-temperature condition of 55 °C. This work provides significant guidance to develop inorganic-rich interfacial chemistry for lithium-ion batteries under extreme operating conditions.

针对极端温度下锂离子电池中锂离子(Li+)快速传输的瓶颈问题，脱溶剂化过程与界面电荷传输均发挥着关键作用。然而，调控溶剂化结构并设计动力学稳定的电极-电解质界面以实现高倍率充放电仍存在挑战。本文引入全氟-1-丁烷磺酸锂(NFSALi)添加剂，以构筑稳定且坚固的固体电解质界面膜(SEI)，实现锂离子快速传输过程与电极材料的结构完整性。在腈基辅助型碳酸酯电解液中，由NFSALi衍生得到的薄型、富氟且含硫的SEI可有效抑制戊腈溶剂在高倍率循环与宽温运行（−40~55 ℃）过程中的分解。更重要的是，在55 ℃的高温条件下，石墨||LiNi0.5Co0.2Mn0.3O2软包电池在3 C充电、5 C放电的200次高倍率循环后，容量保持率可达66.88%。本研究为极端工况下锂离子电池的富无机界面化学体系开发提供了重要指导。